Research Of Intelligent Controlling System Of Engine Cooling System

It's well known that cooling water temperature is very important to diesel engine. If cooling water temperature can keep in the optimal range of cooling water temperature, diesel engine's power can be improved, and less exhaust gas produced, reduce fuel wastage and engine work more calmly. At the same time, with the highly speedy development of electrical technology, a lot of electron parts have been applied on most field of automobile, such as electron fuel eject system, ABS. The development of electrical technology gives feasibility of intelligent controlling system.In conventional applications, combustion engine cooling systems are designed to guarantee sufficient heat removal at full load. The cooling pump is belt-driven by the combustion engine crankshaft, resulting in a direct coupling of engine and cooling pump speeds. It is dimensioned such that it can guarantee adequate performance over the fill engine speed range. This causes an excessive flow of cooling fluid at part-load conditions and at engine cold-start. This negatively affects the engine efficiency and, as a consequence, the overall fuel consumption.Just under this status, a set of intelligent controlling system (ASOICS) was developed for engine's cooling, which is based the improved PID technique, in order to make the cooling system of the engine adapt to different working states automatically. In this intelligent controlling system, EM78P458 Microcontroller was used, NTC transducer with negative temperature coefficient was used for data collecting, and the manipulating job was realized through PWM signal for cooling fan and the circulating pump. In addition to, ASOICS has the functions of display temperature value in line and alarming failures.The corresponding controlling software was designed for this system based on the improved PID algorithms. The PID control principle and improved PID control algorithms; electromotor controlling theory, PWM modulation principle, emulation model and analysis of emulation result is mainly discussed. The emulation result shows that pump and fan can auto-regulate with cooling water temperature. An anticipative effect of correct measurement and accurate control can be reached.